package com.lmy.demo0.utils;

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.lmy.demo0.entity.User;
import com.lmy.demo0.service.IUserService;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import java.util.Date;

    @Component
    public class TokenUtils {

        private static IUserService staticUserService;

        @Resource
        private IUserService userService;

        @PostConstruct
        public void setUserService() {
            staticUserService = userService;
        }

        /**
         * 生成token
         *
         * @return
         */
        public static String genToken(String userId, String sign) {
            return JWT.create().withAudience(userId) // 将 user id 保存到 token 里面,作为载荷
                    .withExpiresAt(DateUtil.offsetHour(new Date(), 2)) // 2小时后token过期
                    .sign(Algorithm.HMAC256(sign)); // 以 password 作为 token 的密钥
        }

        /**
         * 获取当前登录的用户信息
         *
         * @return user对象
         */
        public static User getCurrentUser() {
            try {
                HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
                String token = request.getHeader("token");
                if (StrUtil.isNotBlank(token)) {
                    String userId = JWT.decode(token).getAudience().get(0);
                    return staticUserService.getById(Integer.valueOf(userId));
                }
            } catch (Exception e) {
                return null;
            }
            return null;
        }
    }

